text:
Is it normal to choose a left or right pattern based on the wind direction?
I fly at Las Cruces International (KLRU) which is in an area with high winds (20 knots or more).  My flight instructor wants me to fly the traffic pattern according to the crosswind direction on takeoff.  So if the crosswind on take off is from the right he wants me to fly right traffic, if the crosswind is from the left he wants me to fly left traffic.
I understand the rationale for this.  When you are flying into the wind you have more airspeed and if you suddenly turn out of the wind you lose airspeed and risk stalling.  In fact we have had accidents here where a pilot turned out of the wind on takeoff and stalled because they suddenly lost airspeed.
I have never heard of any guidance in my ground school courses on changing the traffic pattern based on crosswind direction.  So my question is how would an FAA Designated Pilot Examiner interpret me using a non-standard traffic pattern if I fly the traffic pattern according to the crosswind direction?  Could I get in trouble for flying a non-standard pattern even though it would technically be safer to fly into the wind?

I dunno much about this theory. What will happen with your airspeed when you turn downwind or base ? you just made sure you will approach final from a base leg with a tailwind, risk overshooting the final and tightening the final turn

Your instructor is completely wrong. Your airspeed is the same no matter which direction you are flying.(Look at your airspeed indicator!) Your groundspeed varies depending on the wind direction. At a non-towered field you fly the published direction. If none is published, you fly left traffic. At a towered field you fly whichever direction they tell you. Your DPE would probably fail you.

@Radu:  The airspeed would go down if you fly downwind or base of course.  However by the time we turn downwind we are taught that we should at least have an airspeed of 85 MPH in the Piper Cherokee.  So we need to accelerate before we turn downwind.

@JScarry:  What you are saying is not intuitive to me.  Could you please explain this more in an answer?   If you turn out of the wind wouldn't you lose that airspeed?  Isn't that why we takeoff into the wind to take advantage of that airspeed?

What airport and what does the chart supplement say for that airport?

@Ron Beyer:  I fly out of KLRU Las Cruces New Mexico, it is an uncontrolled airport.  All the runways are supposed to be left traffic but I do routinely see people fly right-hand traffic when the crosswind in from the right.

@DLH Hopefully, you were taught to fly a specific airspeed when on downwind, base, final, short final, and in the flare. The airspeed you fly only depends on the aircraft and not the wind speed. Groundspeed varies depending on the direction of the wind and you compensate for it with your crab angle. Your ground track should be the same no matter what the wind is like, but the time it takes for each leg and the direction the nose of the plane is heading will vary with the wind. If the winds are very gusty you should add some airspeed on final and maybe not use the final notch of flaps.

No, it's not. Fire your instructor and find someone who isn't incompetent.

If anything it would be safer to do the opposite so you can have a headwind on base. This reduces the chance of overshooting final, leading to a steep turn at a low speed and a stall.

It is NOT normal to pick the pattern (right/left) based on crosswind.
As JScarry pointed out in a comment, "At a non-towered field you fly the published direction. If none is published, you fly left traffic. At a towered field you fly whichever direction they tell you."  That's how you pick the pattern.

When you are flying into the wind you have more airspeed and if you suddenly turn out of the wind you lose airspeed and risk stalling

This is flat out wrong.
To prove this, find a day where the winds aloft are high, then practice flying constant bank angle circles at altitude while at Minimum Controllable Airspeed.  If your theory is correct, you should consistently stall whenever the nose of the plane is pointing downwind.  (Hint: it won't)
For a second experiment, on a day with a strong crosswind, watch your airspeed indicator as you make your first turn after take off.  Try turning both into the wind and away from the wind. (i.e., try both a left & right pattern).  The airspeed indicator shouldn't show any difference.
Once you are in the air, the only speed your wing cares about is airspeed.  The wing doesn't know if it's a headwind or a tailwind.

You crab left/left aileron low for a left crosswind and crab right/right aileron low for a right crosswind when you're landing. In both cases you want the wind coming from the front.
Landing left wing low might lead to better visibility if piloting from the left.
You should practice to be competent on both sides.
If the wind is shifting from crosswind to a tailwind, you land on the opposite runway. You don't land with a tailwind.
Downwind, however:
The quartering tailwind on downwind might be blowing you away from the runway, or it might be blowing you towards the runway - deal with it. You don't select left downwind or right downwind based on that - you might find yourself in helicopter traffic that way, or maybe uncomcortably close to obstructions. Maybe you can get away with most of the time, but it will bite you on the ass someday.


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Why do some airports have class E airspace to the surface only at certain times?
Below is the depiction of the Truth or Consequences airport on the VFR sectional.  Notice that it states that Class E to the surface is only effective for certain hours.

The Chart Supplement lists the effective hours as 9:00 - 17:00 local (converted from Zulu).  My question is why are the Class E surface hours limited to 9:00 to 17:00 local and not effective for 24 hours each day?  I understand that airspace reverts to less restrictive airspace when a control tower closes but there is no airport tower at this airport or a towered airport anywhere near this airport.

I don”t have a source handy at the moment, but Class C, D, and E airports revert to Class G when communication with ATC to the ground and official weather reporting is not available.

The class E airspace protects IFR traffic departing and approaching the airport from incursions by VFR aircraft.
visibility and cloud clearance requirements for Class E are more strict compared to Class G (which is what the airspace reverts to after-hours).
3 statue mile visibility, 500 below, 1000 above, and 2000' horizontal from clouds for Class E
Compare that to 1 sm / clear of clouds for Class G
You could see that someone pushing the limits of VFR, scud-running to/from the airport might pose a danger to an IFR aircraft on approach to the airport and might pop out of the clouds and get a surprise.
As to the choice of hours, that's likely an FAA decision based on traffic volumes.
Normally you see this at airports that serve rural locations with scheduled passenger service throughout the day (and possibly later at night as well).  Pellston, MI is another airport that comes to mind with a Class E surface area, but it is 24 hours a day.  I think Delta serves Pellston with 1 or 2 flights a day from Detroit.

Re "As to the choice of hours, that's likely an FAA decision based on traffic volumes." - I don't believe this is correct.  See the JScarry comment under question, "I don't have a source handy at the moment, but Class C, D, and E airports revert to Class G when communication with ATC to the ground and official weather reporting is not available."

I don't believe JScarry's comment holds any water, as it has an ASOS (which means it has 24 hour weather reporting) and there is ATC communication available from Albuquerque ARTCC.

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

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text:
What measures are there at Vancouver International Airport to prevent wild animals from entering the airport?
This video shows a wild coyote on a taxiway at Vancouver International Airport (CYVR):

I ask from the standpoint of safety, and menace to aircraft. Does CYVR lack adequate animal control against runway obstructions? What measures are there to prevent such incidents in the future?

I tried to make the post on-topic. I think this is what you wanted to ask about. If not, please feel free to edit again...

It seems that coyotes may not be as big an issue as you might think:

Coyotes are a particular problem for the airport. Formerly, this was
addressed by chasing them around the aerodrome in an attempt to herd
them through the gates. Now, following our review, the coyotes are now
tolerated airside and ‘trained’ to avoid runways, with the added
benefit that they now contribute to mitigating the strike risk by
preying on the bird population.

That's from the website of a company that consulted with YVR on their wildlife management program.
Given the sheer size of a large airport it's unrealistic to expect an 'airtight' perimeter. An animal could run in while a gate is opened, and coyotes can swim so water isn't an obstacle.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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Can anyone identify this biplane with distinct wind screen?
I'm trying to identify the aircraft in this photo of my great grandfather. The photo would have been taken during the mid to late 1920s, possibly early 1930s. He lived in Utah (not sure this helps?). It's hard to tell much from the cropped photo, but it's all I've got. It looks to have a distinct wind screen shape. Looks to be a biplane. Not sure what the logo/writing is on the fuselage. Any info or even guesses are greatly appreciated!

That fellow is Bill Devenish, you can read some of his recollections about the early days of the US Air Mail here - https://www.newspapers.com/clip/11948907/bill-devenish-pilot/

Looking at the ..S Inc above the number 26, it seems that the operator is likely National Parks Airways Inc. / US Mail Contract Air Mail Route 26, (more info).
Your picture looks like this Stearman C3MB:

Source: Aerodacious
Here is another Stearman C3MB, National Parks Airways Inc had several of this aircraft:

Source: agefotostock.com

Seriously... How do you do this???

@Freeman Mostly google + eye for detail + persistence.  Due to the persistence also experience, which helps. First thing I noted was the text on the aircraft. The letter style and the general style of the photo gave me more a late 20s feeling thana 30s feeling. So first google attempt: airplane 1925 utah. Searching for images. One of the first images showed a hangar with "national parks airways. inc" and upon closer inspection also "U.S. C.A.M. 26". Bingo! From there it was just researching that company, following leads, looking at historic aircraft registrations etc.

Nice. Almost need to post that as a "how to" any time someone uses [tag:aircraft-identification].


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What is this jutting structure in the tail section called and what is its function?
I was wondering if there is a name for this particular structure on Su-27 and F-22 and if they serve any function?

re: the F22 part: What is this little "rod" thing on the back of the F-22 for? has an answer with a detailed F22 diagram.

On the SU-27 that is where the rear fire control radar is housed. On the F-22 it is the runaway arrestor hook housing.

runaway arrestor ? Like some kind of Blade Runner ?

@Jeffrey Ever seen the ramps on highways for runaway trucks whose brakes have failed? Similar concept. On a military runway you install something like this https://www.safran-group.com/products-services/emergency-arresting-systems-military-aircraft so aircraft whose brakes have failed and don't have any other means of slowing down other than an arrestor hook can safely come to a stop. And yes, something like a blade runner. :)

@JuanJimenez, do you have a reference for the Su-27 rear fire control radar? I'm curious about that. Thanks.

@Tyler I did a little more research and I think it may be the radar illumination warning system component of the fire control system, and I am not even sure if that wording is correct. There is an SPO-15 Beryoza system for that with an indicator in the cockpit (on the bottom right hand side of the instrument panel), and I think I found that the rear boom also contains the chaff dispensing system. The info I found suggests it is also used in the Mig-29 and Chinese J-11. I am not really an expert on this, I just digged up the best info I could find.


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What does "CATs three and four" mean?
I heard this line in Top Gun (1986) film:

Airboss: Ready Willard and Simkin off CATs three and four.

What does "CATs three and four" mean?

Like the other poster suggested, ‘CAT’ being short for aircraft catapult.  This is a reference to catapults number three and four, sometimes called the ‘waist’ catapults or waist cats marked in red below.


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Were there engineers in airship nacelles, and why were they there?
I am reading some old letters and there's a mention of an engineer who worked for a time in the engine nacelles of the Hindenburg.  He didn't seem to like it very much.
Were there engineers posted in airship nacelles?
Why?
How do you get to one?
If an engine failed, what would be a repairable failure mode from the air?
Or were the engineers just glorified gauges?

There is plenty of information online about the Hindenburg disaster.
The crew manifest lists 17 men as "Engine Mechanic" and 3 more "Engineering Officer" so it is safe to say that there were quite a number of people aboard who were responsible for the engines (and of course other systems in the case of officers).
A page about the Design and Technology of the Hindenburg states:

A mechanic was stationed in each engine car at all times to monitor the diesel and carry out engine orders transmitted from the control car.

How did they communicate?

Orders regarding engine speed and direction were transmitted to the engineering room along the keel and to the four power cars from an engine telegraph located at the starboard side of the control car; the telegraph had toggles to alert mechanics in each of the four engine cars and the engineer’s room of changes in power settings, and could transmit orders for four forward speeds (idle, slow, half, and cruise), two reverse speeds (idle and full), and stop.
Adjacent to the engine telegraph was a tachometer, an altimeter, and a variometer (or vertical speed indicator).
There was also a speaking tube to communicate with riggers along the axial catwalk.  (Communication throughout the ship was normally by telephone, but to avoid the risk of sparks, no electrical equipment was placed along the axial catwalk.)

You can also read all about the accident investigation if you're interested.

The engine mechanics were there for two reasons:

The engines needed to run continuously for 120+ hours during a typical Frankfurt-to-Rio de Janero flight.  For diesels of the era, this means frequent minor maintenance, and occasional major repairs (for example, during the Hindenberg's first return flight from Rio, the #4 engine had a wrist pin failure and was re-built in flight to run with only 15 cylinders).

The engines had to be locally controlled.  It's roughly 150 meters from the Hindenberg's control car to the aft engine nacelles.  Running a mechanical linkage more precise than an engine telegraph over that sort of length is basically impossible, particularly since a zeppelin will flex during the flight.  Electrical controls were not an option because running wiring close to the gas cells was too much of a fire risk.

To your 2nd point, you say such long mechanical linkages "are" (present tense) impossible, but would Bowden cables not have been able to provide such linkage? Apart from the issue that they were invented only a few years prior and were probably not easy to manufacture at such lengths...!

@noughtnaut Nowadays Google doesn't show me Bowden cables longer than 25m for sale. Perhaps friction and elasticity made 150 m Bowden cables unsuitable in the 1930s?

Ah, yes. I hadn't considered friction within the cable. In the days before teflon linings, 150m of sheathed cable might as well have had a knot in it.


text:
If props throw air outwards, why do some prop diagrams show a reduction in airstream diameter behind the prop disc?
If props throw air outwards, why do some prop diagrams show a reduction in airstream diameter behind the prop disc, or are these velocity vectors?

Diagram showing airflow outwards as shown on nap.edu

Diagram showing reduction of airstream behind prop as shown in Zenith, Flying on your own wings.

This is Bernoulli's principle by definition. Flow after the blade runs faster, hence lower pressure and is pushed inwards by atmosphere. Or, think the total mass and volumn are constant before and after the blades, then the flow after the blade that runs faster must be narrower. Also, since some of the flow is thrown outwards at the blade, the flow after the blade would be even narrower.

@user3258438 that's an answer.

The outward movement only concerns the boundary layer, a much smaller mass of air than what is moved by the prop.


text:
What is the minimum glide ratio of a motorized glider?
What is the minimum glide ratio of a motorized glider, enough to climb in typical summer afternoon thermals over a dark field or similar?
In other words, at what minimum glide ratio would a glider be considered more of an ultralight rather than a glider, at least conceptually, or based solely on glide ratio?
I don't think anyone would consider an aircraft a "motorized glider style", irrespective of the class the aircraft is registered in,if the glide ratio is 4:1.
A glide ratio of 20:1 seems like a more realistic cutoff. Is this correct, at least conceptually?

This classification does not depend on the glide ratio. It depends on the "construction rules" under which the  plane is build. They differ for "ultra light" and "normal planes"

The Space Shuttle was a perfectly good glider with a (subsonic) glide ratio of about 4.5:1, and the X-15 was 4:1.

Ability to climb in a thermal isn't dependent only on glide ratio -- it's mainly about sink rate, which is tied to glide ratio by flight speed.

The minimum glide ratio of any aircraft is zero. Just put it into a vertical dive. Of course this is not sustainable; either you overspeed or collide with the ground.
in order to be certified as a powered sailplane (that is bureaucrat talk for motor glider), EASA CS-22.1 demands a ratio of weight to span squared of less than 3. The second limit is a maximum weight of less than 850 kg. That the code gives the maximum weight in Kilogramms and not in Newtons shows that the weight figure limit of 3 needs to be calculated with the mass of the aircraft, not its weight.
Initially, the criterium was a minimum sink rate of less than 1.0 m/s. That number was raised to 1.2 m/s when the first batch of glassfiber models could not meet that target. The mass per span squared rule came into force in 2003.
The defining criterium for an ultralight depends on the local rules and is a maximum take-off mass of 300 kg or less for single-seaters or 450 kg for two-seaters in Europe. Within the ultralight class there is no motorglider category.

For motorglider soaring you are more concerned with sink rate than L/D, because the engine is thought of as an L/D substitute and you are already penalized with a higher sink rate than you normally would because of the weight of the engine and fuel.
The L/D, and the speed at which it's achieved, will determine your ability to get between thermals without having to start the engine, but basic thermalling climb performance is a function of min sink rate and the thermalling speed.  (If you've flown a Schweizer 1-26 which has an L:D of only around 23 but floats like a butterfly and can stay up in very weak lift because it can slow to the low 30s, you know what I mean).
On a good soaring day you will get thermals of up to 600 or 700 fpm and on boomer days over 1000 fpm, so on such a day a glider with a 300+ fpm sink rate can get by quite well.  But as the conditions get weaker late in the day, or on a marginal day, you want to be sinking not too much more than 200 fpm.  If the L:D is not so great, it just means you will be starting the engine more often to get yourself out of trouble trying to run through sink between thermals.
As far as Ultralight gliders go:
The Sandlin Goat soars fine with an L:D of somewhere around 10 (there is no published figure - also, the basic design does not accommodate an engine so you'd have to engineer it).  It's sink rate is well under 200 fpm and can thermal in weak lift and Goats have done pretty long cross country flights if the winds aren't too strong.
The Mitchell Wing had an L:D of 16 with engine and a min sink (I dimly recall of somewhere between 200-250 fpm) good enough for soaring in most conditions except very weak days or late afternoon.
The Marske Monarch was probably one of the best performing ultralight gliders that an average person could afford and could be motorized with an L:D of around 20 and a min sink well under 200 fpm even with an engine.
Then there's the guy who put two Hobby King RC electric motors on a Millenium, which is around 18:1 and I believe sinks under 200 fpm.
There are ultralight gliders with much higher L:Ds but they are super expensive factory builts, way out of my league.
For a homebuilt ultralight motorglider, I'd be happy with an L/D of better than 15, but preferably better than 20, and a min sink of under 220 fpm. I'd power it with electric motors.  Instead of depending on L/D and penetration power, you have the motors.
You could scratch build a Mitchell Wing and power it electrically using RC components for probably under 10K (if you can find plans).

This question isn't answerable in any meaningful way.  There are legal Part 103 ultralights (self-launching sailplanes that meet ultralight speed and weight limits under US regulations) that have glide ratio well above 30:1, and there are commercially sold motor gliders that have glide ratio as low as (as I recall) about 26:1.
Soaring isn't a good defining characteristic, because in slope lift, even a basic Rogallo hang glider can soar for hours, and in strong thermals they have climbed high enough for the pilot to need oxygen.
Minimum sink is a bad criterion, because forward speed contributes to sink rate; of two aircraft with the same glide ratio, the faster will sink at a higher rate.
All we can really say is that a motorized glider can be flown like a glider or sailplane, but has an engine that can be used to take off or climb, removing the need for a tow or winch launch.

Well, I think you did answer the question. Looks like a realistic minimum glide ratio for a motorized sailplane, independent of classification, would be around 26.

The point is that ordinary airplanes can glide well enough to soar, in thermals or slope lift (I've seen a video on YouTube of a Taylorcraft doing so) -- I'd be very surprised if a Taylorcraft or Cub had a L/D better than about 10.  Soaring is about minimum sink as much as about L/D -- and neither one really defines a motor glider vs. a low-loading utility or sport airplane.

Why do you say minimum sink is not a good criterion? If your goal is to stay aloft, it's a perfectly good criterion. Of course, it's not if you actually want to go anywhere else.

@Sanchises "Of course, it's not if you actually want to go anywhere else."  Exactly.  Modern glider tasks all revolve around speed, with the requirement of being able to reduce sink rate enough to stay aloft and gain altitude being assumed.  For sport gliding, you still need more than minimum sink, else an oversize parachute would be the best (cheap, too, compared to any sailplane or even ultralight).


text:
Would a slotted flap still work if the prop is located mid wing between the wing and flap?
Would a slotted flap still work if the prop is located in a slot mid wing between the wing and flap?
This would be for a distributed propulsion application for an multi prop ultralight triplane, where the each prop would need to provide distributed propulsion for multiple wings vertically.

Because I am not sure what your arrangement is, and if I understood well from the description, and in order to avoid confusion, I think the best way to go is to provide a sketch of the cross-section and the general configuration.

Yes.  Inserting a prop aft of the wing and forward of the flap would not reduce the flap's effectiveness.  If anything, the stronger, more concentrated propwash would make the flap more effective.
The answer doesn't change for a triplane.  But off topic, I wonder about how to design a triplane that's light enough to be in the ultralight category, what advantages it would have over a biplane or monoplane.  Commercial interest in triplanes petered out eighty years ago.

The flap will be fine. It is the propeller I am concerned about.
A propeller directly in the wake of a wing, with the propeller axis in the wing's plane, will hit the boundary layer of that wing each time the propeller blades cut through that wake. This means a sudden decrease and increase again in dynamic pressure which results in a sudden change in bending loads on this propeller blade. This will

reduce the lifetime of the propeller due to material fatigue, and
produce a distinct noise at twice the propeller frequency for a two-bladed prop (and at six times its frequency for a three-bladed prop).

It will be better to place the propeller ahead of the wing or aft of it with some distance between the trailing edge and the propeller plane in order for the wake to dissipate and for the dynamic pressure change to become less sharp.
And using several wings stacked vertically has turned out to be a poor solution maybe 100 years ago already.

That much racket for multiple props might well be even noisier than a brace of piston engines.  Annoying when they're all just a few feet from your ears.

The pressure changes at the wing's trailing edge would also accelerate the aging of the relatively fragile wing fabric of an ultralight.


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Does a v-tail offer true 3 axis control in all areas of a basic flight envelope?
Does a v-tail offer true 3 axis control in all areas of a basic flight envelope?
** Based on the comments below, I've slightly changed the question
from "Can a v-tail offer true 3 axis control?" to the above.
I understand in a classic configuration, the ailerons control roll, the elevator controls pitch, and the rudder controls yaw, but in a v-tail, the elevator and rudder are part of the same control surface.
So can a v-tail offer true 3 axis control in all areas of a basic flight envelope?
My gut feeling is .... No!!
I stand to be corrected but, I don't think you can
use a v-tail to fly at maximum AoA during a forward slip with crossed controls).  Eg.  Full right rudder, full left aileron, full pitch up.
Is this correct?

Scotsman fallacy?  What would ‘untrue 3 axis control’ look like?

You do understand that the "ruddervators" can move the same way or the opposite way, right?

For roll, may the ailerons control that, or do you want the V-tail to control that as well as pitch and yaw?

There must be a video of someone doing a full-and-free-movement check on a Bonanza???

A conventional tail only provides two axes of control, pitch and yaw. Why would a V tail do more? As @CamilleGoudeseune says, ailerons control roll. If you are asking whether a aircraft with a V tail can use it in conjunction with ailerons to get all three axes all the time, that is not clear and I think a certified Bonanza is your answer.

@Pilothead it would be a stretch to think that a v-tail wouldn’t produce any roll effect, hence my earlier comment.  Whether it would be usable for any particular purpose is another matter.

Yes they do the job of both rudder and elevator at the same time. They're called "ruddervators".
To provide normal input/output function, you have to operate the ruddervator surfaces through a mixer unit, a mechanical summing device that operates the two surfaces one-up-one-down when providing a yaw force, that is, when moving in response to a rudder input, and both-up-both-down when providing a pitch force, that is, moving in response to an elevator input.
So when you move the stick back and forth, both ruddervator surfaces move up and down together, and when you move the rudder pedals, they both move from side to side together. Moving both controls at the same time results in a "blended" result that achieves the required pitch and yaw force in proportion to the control inputs.
So, for example, stick half way back, both surfaces half way up. Hold the stick at that position, and apply right rudder, the right ruddervator will move toward neutral, and the left one will move up MORE. This keeps the original pitch force in place, while also inducing a yaw force to move the nose right.
You have to allow for the full aft stick + full rudder case in the geometry of the linkage and the travel range of the surface itself, meaning the travel range of the surface must be more than normally required for each movement individually. So, for example, you might give the surfaces themselves 30 degrees of range up and down. Full up elevator might move the left and right surface to 15 degrees up. Full up elevator AND full right rudder may move the LEFT side to 30 degrees up, whereas the right surface might move down to neutral. Move the stick forward a bit while holding the rudder input, and the left surface might come down to say 25 degrees, and the right surface might go below neutral a bit. To accommodate all this, you may have to make them bigger, partly negating the drag benefit of only having two.

With some designs, you simply "run out of travel" in some corners of the envelope- e.g. you can't get full "rudder" deflection while also making a full "elevator" input--

Good explanation but pitch and yaw are two axes and the question asks about three. So either the question is wrong or the answer is no.

I hadn't thought of the question that way. Interesting. If the V is inverted you get a favourable roll with rudder, although I don't know how you could separate the functions.

Does a v-tail offer true 3 axis control in all areas of a basic flight envelope?

This updated question requires an updated answer: a v-tail does indeed provide full 3-axis flight control, until one of the ruddervators hits its travel stops.
When deflecting the pitch stick fully aft, the ruddervators deflect fully up. If we’re inputting pedal deflection on top of that, only 1 of the moving flight controls can deflect, the other one is in its travel stop already. This results in a flight envelope with more limited directional control. Same goes for pitch stick input with full pedal deflection of course.
The 3rd DoF mentioned in the question, roll, will add to the limited control credit per DoF, while not being very effective due to the limited moment arm compared to ailerons near the wing tips.
The 3 DoFs pitch, roll and yaw are mentioned in their order of importance to flight control:

Pitch control is most critical for flight safety;
Roll control most for manoeuvrability;
Yaw control handy to have during sidewind landings with one engine out for instance.

Of course, the above is a generalisation, but does provide the design parameters for the control surfaces. Best to keep them independent - when combining them, an ability to trade in DoFs must be built in: make sure that it is always possible to input maximum pitch control.

This is largely a matter of human conception, because of an arbitrary design choice about controls. But imagine it was another way: Pedals for ailerons, and a single stick for elevator/rudder.
Or, an intermediate linkage which has the same effect, allowing us to keep "normal" controls.
At the bottom of the stick, simply welded to it, is a circular swashplate.  The swashplate corresponds to the vector of force you want from the tail.  Wow, that's super straightforward!
Well now, you can have any number of fins (think fins on a rocket)... simply tie each fin to the corresponding point on the swashplate, phased** so it produces the correct net force to correspond to swashplate angle.  You could have 3 fins at 120 degree angles, and simply attach their Bowden cables to 120 degree points on the swashplate. 5 fins, 7 fins, sure. Asymmetrical fins as airplanes have, not a problem.
The only thing you couldn't have is all fins in the same axis, because then you could only exert force in one axis and you'd be uncontrollable in the other.

Remember that if you want the "stick back for elevator up" paradigm, there will be a conceptual 90 degree rotation on the swashplate, so a horizontal elevator attaches to the top and/or bottom, with rudder on the left.

** However you would have to account for reversing/phase: to illustrate, suppose for redundancy's sake you attached left and right elevator separately to top and bottom of the swashplate. One would need a reverse action so they work together and not opposite.

Sure it can.  A Pelican or V-tail affords pitch control via differential movement of the ruddervators and yaw control via synchronized movement of the ruddervators.

Did you say that backwards?

Hmmm.  Actually I guess it depends on how you look at it. For pitch they both move up or down together. But from a lateral perspective, for pitch one moves left and the other right. And similarly for yaw:  they move right/left together but from a pitch perspective one moves up and the other down.

pitch + yaw, without roll, is still only two axes.

@vsz - OP acknowledges ailerons for roll and is just asking about the empennage configuration.


text:
Are vortex generators considered high lift devices on US ultralights?
Are US ultralights allowed to have vortex generators?
I understand US ultralights are required to have a landing speed of 28mph without the use of high lift devices.  I understand this is so that the aircraft can land at 28mph no matter what, even if the flaps jam.
Hight lift devices are usually moveable flaps which makes aircraft operation more complex.
Would a vortex generator be considered a high lift device, and therefore not allowed to be used to land at 28mph?
As they are non moveable, it does not make the aircraft more difficult to fly.
As they also allow an aircraft to land slower with the same wing area, I would argue that they make an aircraft safer to land.

I don’t have knowledge about US regs about ultralight aircraft, but here’s an interesting article you can check out: Investigating active vortex generators as a novel high lift device.

The definition of an ultralight is very simple and doesn't mention either landing speed or high lift devices. If you have a source that says there are other requirements that aren't in the regulations, could you share a link to it? What makes you think that high lift devices wouldn't be allowed?

@ Pondlife: Thank you for the link and clarification.

Apparently the question was based on a misconception.  But even when you held that misconception, I don't think you really meant to ask "Are US ultralights allowed to have vortex generators?".  I think you really meant to ask whether a design that could not meet the 28 mph landing speed requirement without vortex generators, would be permissible if it could meet the 28 mph landing speed requirement with vortex generators.

The title question is moot as "vortex generator" does not appear anywhere in the FARs or AIM— the FAA does not appear to define it or a high-lift device. From an engineering perspective high-lift devices are temporarily deployable when needed, whereas the vortex generators are an embarrassment, a lifelong drag penalty to fix an unexpected late-stage aerodynamic anomaly.
Yes, they are implicitly allowed on ultralights. Per 14 CFR §103.1 an ultralight aircraft has performance requirement(s) but the FARs generally do NOT specify or prohibit a particular design solution to achieve compliance with the regulations—that could stifle innovation. So the performance requirements can be achieved by any means and since an ultralight has no airworthiness certification, the means can be changed at will!
Thus vortex generators may be used if necessary to achieve the max. power-off stall speed of 24 knots CAS. Likewise high-lift devices. Or anything, really.


text:
If cleared for an ILS approach at the Initial Approach Fix, where should I intercept the glideslope?
I am a brand new Instrument Pilot and the answer that I am looking for is related to good technique and not necessarily not what is legal or not.  My instructor taught me that when flying an approach from the IAF that I should get below the glideslope, meet my minimum crossing restrictions at the intermediate fixes, and intercept the glideslope at the lightning bolt symbol depicted on FAA charts.  However when I took my checkride, the DPE did not want me to go below the glideslope before the glideslope interception point.
My instructor taught me that by leveling off at the Final Approach Fix altitude I can slow the plane down to final approach speed and do the before landing checklist.  I will then intercept the glideslope at the glideslope interception altitude and follow that down.  It seemed the DPE wanted me to follow the glideslope all the way down from where I intercepted the localizer from the IAF.
In practice, and I am looking for answers from experienced IFR pilots, what is the best technique;  to intercept the glideslope at the lightning bolt symbol or when you intercept the localizer?

Does this question help?

@Pondlife:  I have found that question before and was very helpful for my IFR training.  I know that I can't descend below the minimum fix altitudes even when following a glideslope.  I think both my instructors method and the DPE method are legal.  I just want to know in practice what is typically done especially for airline operations because I hope to go to the airlines some day.

There isn't much point in following step-down altitudes intended for a non-precision approach when flying an ILS. It just adds to workload. You want to capture the glide slope as far out as possible, where the sensitivity is lowest, and make the transition from level flight to glide slope descent once.
So if I crossed an IF at the crossing altitude, and inside the IF I could theoretically descend another thousand feet prior to the FAF before picking up the GS, I've just increased my workload because I'm descending, then leveling off, and descending again at GS capture at or near the FAF, and now it's more challenging because things are happening faster, being closer in.  It makes little sense and there is no benefit that I can see.
When you cross the IF at the minimum crossing altitude, you will be 10-15 miles from the runway and well below the GS.  Keep it simple; just maintain that altitude to GS capture and then start down. The higher you are, the farther out on the beam you are, and the easier it is.
If ATC is positioning you, which is the case most of the time flying a STAR in a busy terminal area, the controller will either descend you to the IF crossing altitude or some other altitude, possibly lower if the controller's vectoring altitude allows, and you just fly that to LOC and GS capture (note that the vectoring alt the controller may place you at is unpublished - so if you are below a published alt due to an ATC instruction, and you have a comms failure, you are supposed to immediately climb to the applicable published altitude).
So, when flying an arrival in a busy terminal area in an airliner, you will typically fly some of the STAR segments, then at some point close in, the controller will put you on vectors and have you descend to whatever altitude the controller is using for traffic stream using that ILS, eventually placing you on an intercept heading for the localiser, clear you for the approach, and you just maintain that altitude for Localiser capture and Glide Slope capture. The controller will always make sure that you are placed with ample margin below the glideslope path and if they don't, they've messed up.
I can't speak for Heavies, but in the CRJs I flew we would drop gear and go to flaps 20 to 30 (landing flap is 45, selected farther down), and call for part of the landing checklist, at GS capture. The drag from the gear and flap selection would get you started on the descent, along with the speed reduction for the flap setting, pretty much automatically and you didn't have to make large thrust reductions or trim changes. Full landing flap was selected above 1500 ft, usually just before the FAF.
The most important skill for hand flying ILS approaches is use of trim and (gentle) manipulation of thrust.  I used to have simulator access outside of scheduled training, and used to spend a lot of time practicing ILS approaches on "raw data", that is, Loc/GS needles only, with the Flight Director turned off. Quite a concentration challenge in a jet going 130kt, but if you got it trimmed hands off on slope and on speed, it wasn't too difficult.

This is an excellent explanation of something I’d never even though to consider before.  Thank you.

In the Center, when vectoring for an ILS, we will give you an altitude that will be UNDER the glide slope (but at or above our minimum vectoring altitude) for the localizer intercept vector. Your clearance to join will have a heading to fly, and altitude to maintain until joining the localizer. We do this to ensure you're not "chasing the glideslope" from above, and to preclude any possibility of intercepting a false glideslope.
Vectoring you to the localizer above the glideslope is considered an error.
Essentially, we do the same thing your instructor taught you.

I had a brain fart in my earlier comments. Yes, as you say, 5–9–1 says to vector aircraft to intercept final: "For a precision approach, at an altitude not above the glideslope/glidepath or below the minimum glideslope intercept altitude specified on the approach procedure chart."

@randomhead -I thought you may have misspoke.


text:
Why aren't the left and right papi lights written "in-line" in the lighting icons section of the Jeppesen chart?
Why aren't the left and right papi lights written "in-line" in the lighting icons section of the Jeppesen chart? Although there is REIL on other charts, it is written in line. Could this be because the papi lights are not aligned, or is it because the format is so coincidental at the time of writing? The icons that are out of alignment are not aligned for any of the LTBU Corlu Ataturk airport Jeppesen charts and I have marked them in yellow. In other airports, it is written aligned.

If you request, I can share the Jeppesen charts that I took the screenshots.

Looking at the physical lights, they are aligned.

Yes, maybe. But why is it not aligned in the symbol part?

I have no idea, I was only responding to this part: "Could this be because the papi lights are not aligned" ... they are aligned.

Because Jeppesen likely employs more than just one person to help prepare documents for publishing, and minor formatting details not crucial to compliance with a procedure are probably not specified in detail.
One person lined it up one way, another person lined it up a different way.

Thank you, sir.


text:
Why are there no straight-in landing minimums (only circle-to-land) for this VOR approach at Adana?
When we examine the "VOR A" Jeppesen chart on LTAF airport page 23-4, we see that there are only circle-to-land minimums in the minimums section. When I researched the reasons for using circle-to-land instead of straight-in-land, I found the following reasons:

The final approach course alignment with the runway centerline exceeds 30 degrees.

The descent gradient is greater than 400 ft/NM from the FAF to the threshold crossing height (TCH). When this maximum gradient is exceeded, the circling only approach procedure may be designed to meet the gradient criteria limits. This does not preclude a straight-in landing if a normal descent and landing can be made in accordance with the applicable CFRs.

A runway is not clearly defined on the airfield.

However, when we examine the LTAF airport 23-4 page Jeppesen "VOR A" chart, we see that none of these conditions exist. The approach path is exactly the same as the final approach course (228°) and the descent gradient is less than 400 ft/NM.
So why weren't straight-in-land minimums specified in this chart, and we were asked to apply circle-to-land only with circle-to-land minimums for the airport?

The reasons you found mention "the CFRs" which refers to the United States Code of Federal Regulations, promulgated by the United States Federal Aviation Administration. The FAA has no jurisdiction over LTAF airport and so the explanations you quote are unlikely to apply, at least directly.

I notice that the NAVAID providing final approach course guidance is on the far side of the airport from the final approach course, which is not (in my experience) how things are usually set up. Perhaps that is relevant?

I expect the answer is due to the 591' obstacle within 1-2 miles of the threshold

Because what we call the descent gradient represents the number of feet per NM. The numbers you see in the conversion table are the fpm values, which we call the rate of climb. You can find the percentile of the descent gradient by simply dividing the fpm value by the ground speed. According to the values in the table, our descent gradient corresponds to 5.63% for a descent angle of 3.18°. The percent equivalent of the 400 ft/NM descent gradient is 6.58%. Since the 5.63% descent gradient in the table is smaller than 6.58% (400 ft/NM), it is a correct view to say that...

...it isn't steep enough to qualify for circle-to-land. I hope you can understand the difference between them, @Ralph J.

@RalphJ it would be better to say the gradient is not too steep to not qualify as straight in. And it isn't; 1137' in 3.1 NM is fairly normal.

How are you claiming the descent rate is 400fpm or less after the FAF when this procedure doesn’t have a FAF?

If you read my comment above, you can understand that fmp (rate of descent) and ft/NM (descent gradient) values are not the same things. What we are evaluating here is whether the descent gradient is more than 400ft/NM. When we calculate the descent gradient using the fpm values in the table, we find that it is 342ft/NM (I won't explain how I found it here in detail). So our descent is less than 400ft/NM. That's why I asked my question. @StephenS

Whether there is a FAF or not is not a factor that will affect this situation related to the descent.

@pilot162 Yes, ft/nm rather than fpm.  Still, the second bullet limits descent rate from FAF to TCH, so how can that criterion be met without any FAF?

I believe it is because there is a 591ft obstacle between MAPt and threshold. I have quoted the MOC from ICAO DOC 8168 Volume II for each of the different segments of the approach.
Initial segment (Part I - Section 4, Chapter 3.3.4):
The obstacle clearance in the initial approach primary area shall be a minimum of 300 m (984 ft). In the secondary area, 300 m (984 ft) of obstacle clearance shall be provided at the inner edge, reducing linearly to zero at the outer edge.
Intermediate segment (Part I - Section 4, Chapter 4.3.2.1):
A minimum of 150 m (492 ft) of obstacle clearance shall be provided in the primary area of the intermediate approach segment. In the secondary area, 150 m (492 ft) of obstacle clearance shall be provided at the inner edge, reducing to zero at the outer edge.
Final segment, for non-precision straight-in approaches without vertical guidance (Part I - Section 4, Chapter 5.4.3.1):
The OCA/H for a straight-in, non-precision approach where the angle between the track and the extended runway centre line does not exceed 5 degrees shall provide the following minimum obstacle clearance (MOC) over the obstacles in the final approach area: a) 75 m (246 ft) with FAF; and b) 90 m (295 ft) without FAF.


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Although there are straight and circling minimums in the VOR Z chart, why separate VOR A chart created containing only the circle-to-land minimum?
Although there are straight-in-landing and circle-to-land minimums in the VOR Z chart, why was a separate VOR A chart created containing only the circle-to-land minimum? When we examine the chart images of Çorlu airport that I have shared below, although there are circle-to-land values at the bottom right of the VOR Z Rwy 04 chart, a separate VOR A chart was created using only these values. I don't understand why a separate VOR A chart was created specifically for these minimums, although there is already a chart where these values are specified. To be able to fly without using DME or just to perform a visual descent? I already know that only circle-to-land minimums are used in VOR A, B, C.. charts, but I am not sure what the reason for a separate VOR A chart is for this airport, I would appreciate your help.

The only relevant difference I can see is

DME required.

for the VOR Z approach. The VOR A does not have such a requirement. This allows aircraft without DME to fly the VOR approach.
Note how the outbound leg from the VOR is flown differently. On the VOR Z you fly out to a DME of 7.0 before turning back in (even when later flying a circle-to-land):

On the VOR A the outbound leg is a timed leg of 2 or 3 minutes depending on the aircraft approach category:

Since this is less accurate, the platform altitude was also increased from 2000 to 2300 feet, probably to ensure sufficient terrain clearance when ending up further out than 7 NM for the turn.

I would like to ask a question that is on my mind. It's normal for the minimum to change due to approach requirements, but why are these minimums published as circle-to-land minimums? Why isn't it published as straight-in landing minimums? I'm wondering what makes the difference here. Because, despite no reason, circle-to-land minimum values are published on VOR A, B, and C charts. Why isn't it published as a straight-in landing?


text:
How do you lean mixture using only the instruments on a C172 Skyhawk?
POH manuals always tells to use the voice of the engine as a reference. (Which complicates things a little bit since carbs and fuel injected planes have different "reaction times" for each cylinder)
But how do you lean the mixture without using your ears? How do you lean mixture with only the instruments as a guide?
Lets assume we have a brand new C172 Skyhawk

Depends what instruments you have... Does it have a CHT? Single or per cylinder temp gauge? Manifold pressure gauge? Or just tach? It's actually really easy to tell by paying attention to the engine. As you lean it out the engine will noticably get rougher.

@RonBeyer lets assume a brand new C172 skyhawk

http://www.sweetaviation.com/leaning-procedures/

Are new C172s fuel injected? They could in theory run Lean of Peak for lower fuel burn & cooler cylinders if the injectors are evenly matched.

@CrossRoads I remember all 172S and 172SPs being fuel injected. Correct if I am wrong.

The procedure varies depending on the engine instruments in the panel. Here’s an good explanation using the EGT probe on a Cessna 172.
And here are the manual pages from a Cessna 172SP that explains it.
[


text:
With 77% less wing area than the Lazair Ultralight, how does the Blackfly meet FAA ultralight category requirement of power off stall speed of 28mph?
With 77% less wing area, how does the Opener BlackFly do a power off stall at less than 28mph (or fly with no power at 28mph)?

I understand the Lazair with 140 sq ft of wing area, was able to fly at 25mph ( some sources quote 18mph), with a MTOW of 450lbs.
With the roughly same MTOW of 450 lbs, in order to fly with just a single prop at 28mph, the blackfly would require a wing area of 180 sq ft, according to my calculations (not sure why that's higher than the Lazair above, but at least it's close), but it does this with only about 40 sqft, or 77% less wing area.
In fact the blackfly can fly a lot slower than 28mph. The blackfly can even land vertically.
It does this, like NASA's X-57, by using props along it's wing's leading edges to produce faster flowing air, thereby creating more lift. When flying slowly, it also uses those props to produce vertical thrust offsetting it's weight, so the wings don't have to produce lift equal to it's weight.
What about in a 28 mph power off stall, when those props are not powered?
The ability to stall under 28mph with power off, is required for it to fly in the US ultralight class.
How does it do this?
My gut feeling is that:

Demonstrating that it doesn't stall above 28mph probably takes less then a minute . Maybe the props are still turning at thousands of rpm ( 8,000-12,000??) and probably still producing enough thrust to produce the lift required at 28mph even though they are unpowered.

or ....

Maybe the props are producing lift in autorotation during a decent, just like helicopters do in a power off situation (in an ideal world), which provides enough lift with the wings to momentarily fly at 28mph with no power.  When partially  stalled, I understand wings can still produce 70% lift.

Is this correct thinking?

It's the same voltage, just crazy amount of amps. Obviously you have to size the motors for this increase.  I understand brushless DC motors can also withstand short increases in load.  That's why Tesla plaid can boast 1,000 Hp, but only for 10 seconds. It's called the C rating of a battery. Pretty standard stuff in the MAV world.

Sorry, I disagree. Power is volts x amps. Some of these motors draw up to 180 amps.

Where in the website for the entire corporation does it mention this aircraft's power off stall speed, and what that term actually means for this aircraft?

As per the website, the aeroplane (it's not a registered aircraft) fits in the US ultralight category which as above, requires a stall speed of less than 28mph. In fact, like the Antotov, maybe it doesn't even have a stall speed!

Perhaps the wing section is much more efficient at low speed and high AoA than that of the Lazair?

I'm a bit confused by this question.  Shouldn't the question be:  why does this helicopter have so much wing area?

To put it simply: in a power off situation that thing has flight characteristics of a brick.

No answers people?

@AnonymousPhysicist It flies with it's props vertical, so it's not a helicopter.  Also it doesn't need a helicopter license.....

@AnonymousPhysicist: Let's compare what is comparable, that is the areas of all propellers and wings vs the blades of the helicopter as for the latter, blades are used both for lift and propulsion. The one-seat BackFly area looks already larger than the blades area of a Robinson R22, a two-seat rotorcraft. I'm not even trying to compare their performances.

This machine is capable of vertical flight, and the 3 feet take off roll they talk about is just to maneuver the machine to the right attitude. The wing area (calculated) has to be around 112 sq ft, and wing loading 5lb sq ft. So clearly its clean foils wont b flying this machine at 28 mph, it simply passes through that zone in translative flight. With a 1,000 lbs of thrust from its 8 props this shouldn't be an issue even with some redundancy. For it is said to be able to fly and land safely with any 2 props out even in the same quadrant. Indeed the thrust almost equals 2x the UAW.
Since the props/rotors are fixed pitch I cant see the rather novel suggestion that it can autorotate, although its a neat idea. Perhaps I need to think about that.
Its emergency system is a ballistic chute.
I'll work out the Clmax at 28mph, and an approximate stall speed on a generous lift coefficient and get back to you. Problems, we don't know which data is right as there are 2 designs, one for US ultralight spec and one presumably for Canada. Also the data doesn't completely convince me as the wing area doesn't look right from images commonly found around the net.
I sourced the wing loading from this YouTube video. Other derived data are from the company website (screenshot below) and Wikipedia.

Welcome to aviation SE. This answer would be better if it had a source, but otherwise is a good answer.

Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center.

Well, since no one else is answering this question, I will take a stab at it.
My gut feeling is that the blackfly can still "fly" with power off at 28mph or lower is because it can descend slowly with its props in autorotation.  See pic below.
I understand the Anotov AN-2 can also descend slowly to the ground by pulling the stick full back, with a forward motion of 14mph, and a descent of about 12mph.

Blackfly Autorotation Thrust
Estimated Indicated Airspeed, IAS:28mph
Estimated Descent Angle: 21 deg
Estimated Descent rate = IAS x sin x radians(angle): 10mph
Estimated Descent, ft/min:   870 ft/min
Estimated Descent, ft/s: 14.5 ft/s
Estimated Prop dia: 1.5ft
Area, Single Prop: 1.8ft2
No. of props: 8
Total Prop Area:    14.1 ft2
Rho, imperial:  0.0765 lbs/ft3
Autorotation Thrust, T=2 x v2 x A x rho: 450lbs
Weight: 450 lbs
Conclusion: The thrust by the props
in autorotation produced when descending
at roughly a parachute descent rate of 10 mph
or 870 ft/min is equal to its weight.
Therefore the blackfly could potentially
"fly" under 28mph, as long as the descent rate
is less than 870 ft/min, and an angle of descent
of roughly 21 deg.
In actuality, this might even be slower due to
fuselage drag. Also, you might want to have the props
rotated at say 45 deg, not 90 deg, for a partially stalled wing
so you can use your elevons for directional control.
Is this correct thinking?

Hmmm... good thinking, I completely disregarded the possibility of autorotation. Unfortunately I'm not mathy enough to verify if your calculations are correct.

Propellers with fixed pitch can only result in drag. You need variable pitch propellers that stores the energy in the rotor for release at a later time via variable pitch. For small to rotors with low inertia this idea doesn’t scale that well.

ok now I promised to do some work on the lift coefficient, which is work that requires  gross weight, a wing area, and in doing so gives us a stall speed.
Preliminaries first, this is a tandem wing aircraft, therefore there is a difference required between the front wing and the rear for safety. The front wing must stall first, so that the machine dives away forward, picks up airspeed and recovers. Conventionally, we satisfy this by increasing the lift coefficient of the front wing or canard to 2.0. Given these are unflapped wings were we would expect a coefficient of 1.4 clean. This means the aft wing or mainplane has a working coefficient of 0.8.
Given all that we can gather values, the video tells us the wing loading is 24.5 kg/M2, which is 5 lb sq/ft. Given a gross weight of 563 lbs (from data), that gives us a wing area of 112.6 sq ft. Wing area each wing (which look identical) is therefore 56.3 sq ft. With each wing at 13' 7' (13.58') the wing chord of 4.14 ft satisfies the area.
So lets plug it all together, the dynamic 'slug' is set at sea level value, which is the weight of a cu ft of air / the dynamic of 32.
Vstall = the root of (2 x GW) / (slug x wing area x lift coefficient)
which equates to the root of 1126/(.00238 x 112 x 1.4 = 54.9 ft sec, or 37.3 mph)
to satisfy a stall of 28 mph we rearrange the terms
2x GW) / (slug x airspeed ft sec x area)
plugged in: (2 x 536) / (.00238 x 41.16 ft sec x 112)
the Cl averaged across the wings is therefore 9.8, which is quite unrealistic.
Just an observation, but it is hard not to notice that the CG seems well aft of what I think is desirable.  The weight distribution must be biased to the canard so that the fuse or higher lift coefficient stall can promote the machine to fall forward and recover airspeed. Im nursing the summation that the machine is not being required to address conventional stall behaviour, which I think is dangerous. This is unless, the quite different configuration of this aircraft somewhat deceives the eye, in that to look from the wing plan view instead of the machine as it sits flat on the ground, the CG is then correctly located.
cheers
EDIT: I found some good photos that conceivably make a kind of 3 view by eye. I think I can place the CG as the CG of the pilot. Looking down on the aircraft it does seem the CG rests where I would expect it should. There is quite a difference between the side profile and the plan view. It really is a very clever design, but I enjoyed chasing the designers tail and working it out.

Did you mean to post this as a second answer? I think it would be better as an edit to your previous answer.

No I would appreciate leaving them both independent of each other, as one sets up the 'scene' and the remainder uses the data from #1 for the workings.

See What's our policy towards multiple answers from the same user on the same question?

This isn't really a separate answer (as in, a different answer from the same person); it's an addendum, and as such ought to be edited into your original answer.  I'd suggest looking up how to format your posts, too, so it doesn't look like a wall of text even with good paragraph breaks.  Headers and subheaders make an answer (or question) much more readable beyond 3-4 paragraphs.

I see theres a delete flag, well go ahead and have at it. Its not me that needs you or looking for answers. cheers


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Is it fairly common for student glider pilots to have wing tip strikes, especially in gusty cross wind conditions?
Is it fairly common for student glider pilots to have wing tip strikes, especially in gusty cross wind conditions?
I understand gliders are landed level, slow down and then the wing drops onto a wing tip wheel or skid plate when coming to a stop.
Which begs the question, are gliders more prone to wing strikes by student pilots prior to or after landing due to the mono wheel arrangement and low wing tip clearance, or have poor cross wind landing ability in gusty conditions (say 10-15mph gusts above the headwind) when compared to a tail dragger or tricycle wheel arrangement?
Yet thousands of gliders around the world are used every week with the mono wheel arrangement, with a mid wing arrangement that is only 2-3' off the ground.
My gut feeling says no, as gliders have been around probably for 100+ years and they would have changed from mono wheel to a tail dragger, at least on the trainers by now if wing strikes were common among student glider pilots. This is probably due to the lateral stability of a long wingspan and the mid wing arrangement means the glider is landing in a nice stable pillow of air in ground effect.

I don't know this for a fact, but I wonder if the change on the Lazair was more to improve taxing or takeoff, rather than actual landing?  Actually are you sure that was "Lazair"-- when I google it I see a high-wing ultralight that seems unsuitable for a single main wheel.  I do however see a reference to widening the track of the conventional (tailwheel) gear here https://wiki2.org/en/Ultraflight_Lazair

For some reason I thought I saw a prototype with a mono wheel, but now i can't find it.  Maybe I was wrong. I'll change my post. Some land on a mono float though.  I know the track was widened from 26" to 46", the original needed a wing walker over 7mph cross wind. Source: wiki

No it never had a mono wheel. I taxied one around in Port Colbourne in 1979, although I didn't fly it and almost bought a kit.  All the same, you wouldn't want to take the thing out in 15-20 mph winds.  Like most ultralights, they are "calm weather" airplanes.

Training gliders like the Swietzer 2-33 often have small wheels on the wing tips: https://en.wikipedia.org/wiki/Schweizer_SGS_2-33  I would imagine most either have wheels or some sort of skid, because as you come to a stop, one wingtip or the other is going to drag on the runway.

Most gliders have dihedral, giving more wingtip clearance than you probably are envisioning.  Many glider pilots routinely use the wing-down (slipping) method of crosswind correction.
As far as general handling while landing in gusty crosswind conditions, most tailwheel airplanes sit in a much more nose-high attitude than most gliders, and have the landing gear much further forward ahead of the CG, and therefore are much more prone to ground-looping.  And groundloops often involve wingtip contact with the ground-- on the downwind side.
On the whole the crosswind limits below which a safe landing without damage to the aircraft can reasonably be expected, are likely higher for most gliders than for most tailwheel light airplanes.
As for the part of your question contained in the actual title-- no, it is not common for student glider pilots to strike the wingtip into the ground before the main wheel touches.

Is it fairly common for glider students to have a wing strike just after they have landed, when in gusty or cross wind conditions: 1. without a ground loop, 2. in a ground loop?

Not really. The training gliders students typically learn in have more tip clearance than "regular" gliders so there is more tolerance for mistakes, and the instructor normally catches things before it gets out of hand. And a student won't be allowed to fly in crosswind conditions that are beyond their ability to cope, and they soon are able to cope. It only takes a degree or two of lowered wing to generate enough slip, so it's not as obvious a problem as it seems. Power pilots have a misconception that gliders are barely able to cope with xwinds but when you fly them, it's not so hard at all.

Actually, the biggest hazard in crosswinds is getting caught by the wind gradient several feet off the ground as you start to put in slip.  If you are at 10 ft agl and allow the upwind wing to come up from a gust say, the upward wing moves into the faster moving crosswind flow due to the wind gradient, and it starts to try to tip you over to the downwind side.  This is a bigger hazard than tip strikes while landing.


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What is typical sink rate of sinking air, and the typical rate of climb for a glider with a sustainer engine?
What is the typical rate of climb for a glider with a sustainer engine with only lift provided by the engine (no thermal lift, ridge lift, etc.)
I understand a self launching glider is almost like a modern ultralight with motors in the 80 Hp range. That probably puts the rate of climb at 400-600ft/min for a weight of 1,200lbs.
In Canada, the light aircraft specifications for homebuilt type aircraft specify a minimum rate of climb of 300 ft/min, which is at the low end of what many modern  homebuilts are capable of, at least those with around 80 Hp engines.
I understand gliders with sustainer engines are meant to "sustain altitude" and cannot self launch. I'm told they are typical about 20 hp.
Yet, what happens if you are gliding over a flat farming region just prior to sundown, thermal lift is long gone and you are "in sink", i.e. in a sinking air region with 100 ft/min sink, and your glider can only climb at 50 ft/min.  This means you're going down at 50 ft/min, no matter what. Having said that, I understand sink typically stops several hundred feet off the ground, which means you won't be slammed into the ground by the sink, but it also means you would have to fly below 1,000ft obstacle clearance and less than 1,000 ft above ground level ( AGL)
I'm sure there is a typical sink rate of descending air over fields and a typical rate of climb even for sustainers.  Just wondering what those two values are.
I would imagine that the typical rate of climb of sustainers is engineered to be above a typical rate of descending air in sink.

There's no way to give you a hard answer. Sink over 500 fpm is unusual unless you are right next to a strong thermal (it's vertical circulation in the end).  Flying around at dinner time, most of the thermal activity has petered out, and so has most of the convection-related sink.  I would be surprised to hit sink more than a couple hundred fpm at most, and that may be more due to subsidence (and therefore more widespread) than convective activity.

Any  idea on a typical rate of climb for a glider with a sustainer engine? With 20 Hp, I'm estimating it would be only 50 to 100 ft/min.

20 HP will make about 80-100 lbs of thrust. A single seat motor glider with just moderate performance, say 30:1, weighing 600lbs all up, will need 20lbs for level flight with the rest available for climb, say 70 lbs or about 17 thrust HP lifting 600 lbs.   It should do better than that.

This question seems poorly framed (what does "typical" mean, when up and down drafts can vary widely, depending on terrain, atmospheric conditions, etc. and when there are a variety of aircraft that might be considered?), and not very practical either, since a pilot will not intentionally stay in sinking air in a glider for any longer than absolutely necessary.


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Was the adoption of conventional tailplanes as 'everyday aircraft' inevitable, or are there other designs that can be just as good?
I originally asked a variant of this on Worldbuilding.SE, but they didn't seem to like it. So I apologize if it's out of place even here.
I ask, because I've been forming in my head an alternate history or two that would logically involve a completely fresh start to aviation; no Wright Brothers, no Otto Lilienthal -- the entire world looks slightly different on a political map.
Because the world is different, it would be lazy of me to just import elements of our timeline without understanding why things developed the way they did. Our world, in general, appears to have rolled with canard planes and later adopted the tailplane for just about every conceivable function for fixed-wing aircraft.
That alone seems to imply that the tailplane is the superior choice to any other design, but is it really? Or was it just a case of technological and economic inertia?
Since 'superior' can be subject to opinion, I'll try to narrow down some criteria:

The design has comparable advantages in stability, lift production and maneuvering.
The design has comparable economic advantages; it doesn't necessarily require more time and resources to build and maintain.
The design does not (necessarily) incorporate concepts that require an advanced and well-developed understanding of fixed-wing aerodynamics. These would be among the early aircraft designs, or at least a short time into successful flight, so things like vortilons, fly-by-wire, etc. would not be present.

There are definitely plenty of wacky creations like Burt Rutan's Quickie, the V-173 and Miles M.39, but I'm sure there are good reasons none of them ever became popular...right?

Related: Why is the use of tail-down force so common?

If you write an optimizer which modifies the wing spans of a virtual aircraft, you will end up with a big wing in the middle and a smaller one at the tail if your goal was to achieve good performance, a wide cg range and docile behavior. So yes, a concurrent evolution would also result in a conventional layout.
Why no canard?

The forward wing is more highly loaded for stability. Adding control surfaces there would reduce the possible control effectiveness. Putting them at the large rear wing will result in higher stick forces and higher lift changes for the same pitch moment changes.
For the same reason, the wing cannot utilize its full lift potential because the canard has to stall first.
Since the wingspan of the canard is smaller than that of the wing, the wake of the canard will hit the wing and disturb the lift distribution over span there.
For directional stability a tail is still needed, even though it is only used for vertical surfaces. Alternatively, the canard wing can be swept and winglets be used for directional stability, but adding sweep will reduce the efficiency of the wing.

This all puts the canard at a distinct disadvantage. It works, but comes at a price.
Why no flying wing?

Flying wings have low pitch damping and a very limited center of gravity range.
They often cannot have trailing edge flaps for extra lift during slow flight, so their take-off and landing speeds are higher than those of a comparable tailed aircraft. Or the wing loading has to be made lower, which hurts at high speed.
Even though a good flying wing design has sweptback wings, they are poorly suited to high transonic speeds. Their wing airfoils cannot have rear loading, so the critical Mach number at the same lift coefficient is much lower than for conventional configurations.

The SWIFT (Swept Wing Inboard Flap Trim) ultralight glider did use a flap.  I wonder why the concept wasn't applied to other flying wing designs?

@JohnK: A small inboard flap is possible with enough aspect ratio and sweep, but its effectiveness is rather limited, especially when compared to the possibilities of the conventional configuration.

Analysis of the canard is highly complex. The control canard can be extremely effective. Yes the main wing operates further from Clmax but it also tends towards being smaller and lighter because the foreplane does some of the lifting for it. Which of these two opposing effects dominates depends on many other factors. The Saab Viggen offered a (patented) breakthrough in which the canard airflow interfered constructively with the main wing, actually improving its performance. But it is hard to give it safe stall characteristics.

@GuyInchbald: The main wing is actually bigger than in a conventional design in order to maintain enough stall margin when the canard stalls. It is simply less well employed and put at a disadvantage by the existence of a canard ahead of it. Things improve when both have substantial sweep, but then the canard is basically the same as a LEX.

@Peter Kämpf: You have evidently come across only half the literature on the subject, evidently the less complex half. I would suggest you read up on the successful designs such as the SAAB Viggen a little more.

The canard layout has serious limitations that the tail does not.  The biggest one is getting the desirable pitch-vs-speed response to give good pitch stability, with the proper stick-free speed-seeking characteristics, while having adequate low speed authority.
With the tail at the back in the airplane-as-a-seesaw configuration, it's easy to get the proper responses (speed up, pitch up, slow down, pitch down, etc.).
With a lifting surface at the front, (airplane-as-a-table-configuration) the required pitch response to speed has be obtained by using a canard airfoil with a steeper lift slope than the main wing, so when you speed up, the airplane pitches up, and vice versa.  With a regular tail, the airfoil can be a sheet of plywood and it still works fine.
The Rutan designs early on used a canard airfoil developed by the University of Glasgow that had the required lift slope characteristic.  Unfortunately this airfoil was very sensitive to laminar disturbance and flying in rain could have a huge effect on trim (they would pitch down in rain, not out of control, but enough to be a problem).  A bandaid solution for this was adding Vortex Generators to the canard.  Later a new airfoil was developed that didn't have the rain sensitivity.
Almost all of the canard's theoretical benefits were negated in the real world, which is the real reason the configuration is rare.  It's not some anti-canard conspiracy; they just don't work as well in the balance of compromises that makes an airplane.
Yes they can't stall/spin, but you can make a normal airplane do that as well (Ercoupe). The VariEZe/Long-EZ have high take off and landing speeds and yes you can't spin it, but if you put it down after an engine failure you are probably going to get hurt anyway.
Rutan developed a sailplane called the Solitaire that used a canard surface.  You'd think that would optimize the canard advantages to make the perfect sailplane.  It was unsuccessful because it developed high sink rates at thermaling speed (you are normally turning just above the stall, at min sink speed).  He's a brilliant guy, but all Rutan's designs are homebuilts or specialty aircraft where the limitations can be lived with.
What about mass production?  Well, you have the Beech Starship.  A catastrophe for Beechcraft, nearly bankrupting them.  The only place you see canards in the production world are as supplemental surfaces to the primary stabilizing surface, the horizontal tail.
The Wrights put a lifting surface at the front because it seemed like the logical thing to do at the time. The surface moved to the back pretty quickly as airplanes progressed.

The Starship failed because Beech pioneered all-composite construction before the technology was mature. The Wrights put the canard there to deliberately destabilise it in pitch, under the false impression that a stable plane could not be manoeuvred. They changed their minds once manouevrability of a stable plane was demonstrated. On the other hand the first plane to fly nonstop around the world, the Rutan Voyager, was a canard, so it is far from a no-hoper: you just have to be as smart as Burt Rutan to get it right. ;)

The Wrights originally adopted the canard to make the plane unstable, in the mistaken belief that a stable plane would respond only sluggishly to the controls. The first plane to fly in Europe, the Santos-Dumont 14bis, was a canard which managed to have the very problem the Wrights adopted it to avoid. A few years later Horatio Barber in the UK produced a stable and flyable canard plane, the Valkyre. It proved to have safer stalling characteristics than its contemporaries. In parallel and also in the UK, J W Dunne developed the tailless swept wing, also for its stability and safe stalling properties. Meanwhile others in France, the US and the UK, the Wrights included, developed Wright types with both a tail and a canard before abandoning the canard. Both the canard and tailless types proved too difficult to get right, while the tailplane was a lot more tolerant of bad design and easier to adapt to circumstance. The French led the emerging fashion but it would have made little difference who did, and by the time Bleriot flew the Channel, the tailplane was already becoming conventional in all three major aviation nations.
Eventually the other types would find suitable niches, some quite sizable, but overall history could only ever have gone one way.

Different applications have different optima, in aviation as in most other things.  If you're maximizing one combination of overall performance, pilot forward vision (in the nose-up landing and taxi attitude of a conventional gear design, which was nearly all there was before 1930), and cost/weight of construction, it's pretty easy to see you get pretty much the designs we had then, which lead to the designs we have now.
That said, if something had been invented earlier or later than it was, it might have changed the end result fifty or seventy-five years down the line.  If tricycle gear had become popular before aircraft carriers won the Pacific theater of naval combat, we might have seen designs in service by 1945 that were abandoned in our history -- aircraft like the Curtis XP-55 Ascender, for instance, or the broadly similar German and Japanese designs that never saw service, despite promise of better performance and flight characteristics than the tractor engine, conventional layout designs that went before them.
Other factors might as readily have resulted in tailless aircraft coming to the fore (like the Cutlass jet fighter of the 1950s, or YB-49 bomber) -- either those or canards can be made stable enough and give enough performance for a given task, in general, but the industry has so much more experience with conversational designs that designers and customers alike are more comfortable with the elevator in the rear and propeller in front, and never mind how well Rutan's odd-looking designs fly.

As far as the rear mounted horizontal stabilizer, nature's inexorable trail and error over unlimited time has yielded the answer.  Canards do work very well with deltas, but deltas are not nearly as efficient as straight wings in the all important lift/drag analysis.  Birds have over 100 million years of history.  Theirs are behind the wing.
But for human flying objects, arrows have been around much longer and indeed form part of the understanding of flight.  Archers are able to maintain considerable hitting power at long range by setting the CG forward so the arrow pitches down to maintain speed, just like an airplane.  The rear mounted tail plane also helps to pitch the nose down as the plane sinks.  Both these factors help regain airspeed and proper Angle of Attack in the event of a stall.
Vertical stabilizers have more possibilities and can be mounted on the wing tips as well as on the rear of the fuselage.  But with active onboard trim computers, we become more like birds, finely controlling our aerodynamic surfaces.  This will help eliminate the need for ponderous, drag producing stabilizers and lead to greater fuel efficiency.
Planes that "eat like a bird".

To fly, a wing must maintain its angle of attack within a certain range. If the AOA is too low, the wing produces no lift. If the AOA is too high, air moving over the top cannot follow the wing's contour, separates, and causes a reduction in lift (aerodynamic stall). Designs that employ passive stability to maintain an appropriate AOA will make the aircraft safer to fly because they don't require the pilot to be actively monitoring AOA and making constant corrections. The tailplane configuration places the aircraft center of mass forward of the wing's center of lift, with the tailplane creating a counterbalancing down force. As the airspeed increases, lift increases, and so does downforce on the tailplane, causing the aircraft to pitch up and slow down. As airspeed decreases, lift decreases, and so does tailplane downforce, causing the aircraft to pitch down and speed up. Similarly, if a disturbance pitches the nose up, increasing its angle of attack, it reduces the downforce on the tailplane, restoring the pitch attitude; if a disturbance pitches the nose down, this increases the downforce on the tailplane, again restoring attitude. The tailplane configuration is thus naturally (passively) stable in pitch, strongly favoring its use.
A drawback of the tailplane configuration is that some of the wing's lift is opposed by the tailplane, which makes it less energy efficient than other configurations such as the canard. A canard configuration can also be designed with passive stability, but it is more difficult to get right, especially when it comes to things like stall recovery.

This is quite wrong. The tailplane seldom exerts a significant downforce, except during takeoff and landing. The force it exerts is downward only relative to the wing lift and in the lifting tail it remains modestly upward throughout. Moreover the tail does not stabilise speed as suggested.

That alone seems to imply that the tailplane is the superior choice to any other design, but is it really? Or was it just a case of technological and economic inertia?

A bit of both. And beside the technological features discused in other answers, one should not forget about history here. The tail plane/front engine has its disadvantages, but at the same time an incredible development advantage due WW2. Standard setup planes allow very agile configurations, something fighters depend on. And while many other configurations have been tried during the war, most attention was given to standard ones. As a result knowledge for their construction was widespread after the war and used for civil developments.
It's a bit like the question why the once leading electric car was put out of business by petrol cars - again, WW1  played the major role. While loading batteries isn't a hassle in a developed civil environment, it becomes almost impossible under war conditions - here petrol holds an incredible logistics advantage as moving a few barrels of petrol is easy done, in contrast with setting up power generators to load batteries.
It's not always the war, as economic scaling works as well - like why our modern computers almost all reassemble at the core simplified mini computer constructions - and huge efforts are now added to 'de-simplify' them again.

The advantages of the conventional tail and the internal combustion engine were established far more broadly than  by a couple of military campaigns. Meanwhile the classic Von Neumann architecture of the digital computer has applied from the very first mainframe - the mini-computer era and simplifications such as RISC have nothing to do with the system architecture.

Calling WW2 'a couple of military campaigns' is a steep one. After all, these years cover most of the development - and basically all commercial planes after were based on military designs. Also, the evolutionary narrowing of minis is neither about Von Neumann nor RISC, but the reduction of any higher function to the most basic function and replacement of advanced I/O by memory mapped ports. This happened when they were introduced, decades before RISC.

You mentioned two wars not one. Understanding and wholesale adoption of the conventional tail were essentially complete by 1918. I'm not sure how "advanced" data i/o was before universal data buses and memory mapping were introduced, but I'll grant you it could get complicated.


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Has a scheduled passenger flight ever stalled because of shifting cargo?
Has any scheduled commercial passenger - not cargo - flight ever experienced a stall due to cargo shifting, like the National Airlines Flight 102 did, back in 2013?
Please note I am specifically asking about scheduled airline flights with passengers on board, i.e. not cargo flights. No incidents involving tanks or other military equipment.

Possibly

National Airlines is a commercial operator, they aren't part of the military

@Pondlife Yes, but this wasn't a commercial flight., it was a military one.

@Cloud It was a commercial flight, they were just carrying military equipment. Just like putting military personnel on a domestic flight doesn't make it a military one. It was a commercial operator on a commercial flight.

As Ron said, that flight was a commercial one. I don't know exactly what you mean here, but are you asking about a scheduled airline flight with passengers on board, i.e. not a cargo flight?

National Airlines was/is a civilian Part 121 or 125 carrier. The military regularly contracts with civilian carriers for movement of cargo and personnel, but the flights are commercial flights and are not distinguishable from other commercial flying insofar as the rules. I flew many such flights, and occasionally the disparity between military rules and FAA rules did cause confusion. Both sets of rules are more or less restrictive than the other depending on what area of operations you're talking about. Military commanders can waive some rules. Airline managers cannot waive FAA rules.

I notice that the link in the OP does not include the video of the crash. Go to https://www.youtube.com/watch?v=qPngBazzce4 for that. It is dramatic, to say the least. Also, on a far more minor note, cargo shifts to happen, but they're usually just a single ULD and easily handled. See the last paragraphs of http://terryliittschwager.com/Journal/1999-01-23.html for one such shift.

This accident had more to do with the cargo shift taking out the horizontal stabilizer jackscrew than the actual shift in weight changing the plane's center of gravity.

@Pondlife Please understand what I'm asking. Obviously most commercial flights do not carry tanks on them... so for the sake of clarity I have edited the question. Please feel free to re-edit if this isn't good enough

@Terry But I must admit, I enjoyed the read, especially the " put-your-head-between-your-legs (and kiss your ass goodbye as the saying goes) drill" xD

@Terry I read the whole thing and think I will now binge read all of your journals :)

@Terry the video is not in the question because it is not really needed to understand the question.

Yes, a LET-410 crashed in the DR Congo, apparently because a crocodile escaped. Passengers trying to escape the animal apparently caused enough of a load shift to result in a crash.
Not a shift, but Air Midwest Flight 5481 crashed due to a combination of a  weight and balance error coupled with a misrigged elevator.
In general, it's harder to have a significant load shift on a passenger aircraft since it's easy to check the distribution of passenger loads, people are well restrained by seat backs, and unless something else is catastrophically wrong (fire), passengers don't all get up and move to one side of the aircraft.

If you include tailstrikes in your definition, then yes. There has been at least one case in Italy involving a takeoff with an A320 where the aircraft was loaded without any baggage in CP 1. Although it did not involve a shifting ULD, the improper loading did contribute to the incident.


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Are the FAA laser exposure maximums set too high?
I recently came across the FAA's press release regarding the diffracting laser lights which appear every Christmas:

You might not realize this, but a well-meaning attempt to spread holiday cheer has the potential to create a serious safety risk to pilots and passengers on airplanes that fly overhead. So please make sure all laser lights are directed at your house and not pointing towards the sky. The extremely concentrated beams of laser lights reach much farther than you might realize.

The FAA makes it clear that there is a substantial concern regarding laser-blindeness among pilots.  And its clear the FAA will do something about it.  But what can they truly do to help, within the limits of their authority?
Doing some research (okay... fine... having Google link me to Wikipedia), I find the following limits:

0.05 µW/cm² - Laser Free Zone
5.00 µW/cm² - Critical Flight Zone (10 nmi around airports)
100.0 µW/cm² - Sensitive Flight Zone
2500 µW/cm² - Normal Flight

I did some calculations on a class 3R laser pointer with a safety factor of 3 built into them, and got results which were quite in line with this infographic from Laser Safety Facts.  I'll report the professional numbers, rather than my own, just to avoid uncertainty.  These are the distances at which point the laser pointer crosses the threshold and it becomes illegal to point them at an aircraft (according to laboratory conditions.  Obviously one should never intentionally point a laser pointer at an aircraft, regardless of power):

10,995 ft - Laser Free Zone
1,096 ft - Critical Flight Zone
245 ft - Sensitive Flight Zone
104 ft - Normal Flight Zone

(Note: these numbers are consistent with those linked in this answer to a related question, and come from the same site)
With a minimum altitude for flight over urban terrain set at 1000ft, it appears it is not possible for a standard green 3R laser pointer to cross the threshold chosen by the FAA for critical flight zones, much less normal flight zones.  Over rural areas, the lower 500ft minimum altitude could play a part, but would still never reach the normal flight range.  Naturally, there is the possibility of violating requirements near or within a critical flight zone, where landing aircraft may be much lower than 1000ft, but it shows the level of concern that the FAA has for that given brightness threshold.
This seems quite inconsistent with the FAA press release.  The holiday laser light shows have a substantially higher dispersion than a typical laser pointer (indeed, they start by fracturing it into dozens of smaller points with cheap optics).
It's possible the FAA is intentionally overstating the risk, but its also possible that the thresholds chosen are simply much higher than is truly comfortable for pilots.  With thousands of laser strikes reported per year, pilots' comfort level is clearly surpassed by laser strikes on a regular basis.
Does the data suggest the FAA limits are too high to sufficiently protect pilots?  (I'd ask whether they should be changed, but that would turn into a quagmire of opinion based regulation changes quite quickly)

I think the question needs a bit of clarification:  do you want to know about the risk of eye injury or the risk of distraction?  These are completely different issues.  Beware that laser safety labels found on lasers often have little relation to reality, and this is especially true for cheaper consumer lasers.  In my experience, the laser safety labels never include the nominal hazard zone, which is essential information for aviation safety but does not matter at all for indoor use.

If your visible-frequency laser is not able to create a distraction from 1000 ft away at night when visibility is good, I would say you've got a broken laser.  I've used very many lasers but never flown an aircraft.

@AnonymousPhysicist I'm trying to grapple with what appears to be an inconsistency in the messaging.  On one hand the argument is that lasers can distract pilots, so you should never ever ever ever do anything remotely like pointing one to the sky.  On the other hand, when you look at the numbers they use to define "distraction," a reasonable IIIa or 3R laser falls short of the threshold, and these holiday devices are well over 100x weaker than that!  It would be like the DOT saying "driving fast is incredibly unsafe.  Never do it" and then setting the speed limits to 150mph.

Distraction is not related to the class of a laser.  A Class 1 laser may cause distraction.

@AnonymousPhysicist The FAA defines the power density (uW/cm2) which is considered to be a distraction to pilots.  Combine the class (which defines maximum power) with a divergence of the beam (which is reasonably well known for laser pointers as a class of devices to be somewhere on the 0.5 to 1.0 mrad range), and an altitude and you get power density.  If it turns out that power density was not the correct unit of measure for the FAA, that would probably a decent frame-challenge answer: the limits aren't too high because they're the wrong measurement.

I think your most recent comment makes a lot more sense than the question you posted.  An edit is called for.  Presumably the FAA uses the power density for the most distracting wavelength, which is some kind of green.

@AnonymousPhysicist So I should make an edit to include the information in paragraph 4 (the first bulleted list)?

A non aviation reason the FAA may be taking the position they do is that many LASER devices are marketed as 'brightest' and sold to people without means to measure actual power level, so it is normal for devices sold to not conform to standards. Further the power is adjustable in many devices so consumers may adjust upwards for a better show regardless. Source - have access to power measuring equipment, ebay and respect for my vision. So FAA cannot take it on faith that consumer devices really are 'safe' at the ranges listed.
Related, it is in the FAA interest to not to normalise aircraft being illuminated with LASERs, so if they push for 'any LASER observed by an aircraft should be investigated and considered a crime by default' they side step the questions of 'was the device legal' and 'was it pointed intentionally' when someone does maliciously dazzle pilots.

Having a laser illuminate your cockpit is a distraction, at least.  If it's a holiday display, you might get one or two quick flashes out of it, but at 150 to 250 knots, you've flown past it before you'll get more than that.  And, above 1,000', as the OP points out, you're beyond the range where the household displays have the power to harm you.  So the distraction is the main factor there. And a single blip, flying past a brightly lit up neighborhood, doesn't amount to all that much, generally.
When you have a bad actor who is using a green beam to intentionally illuminate an aircraft, that's an entirely different story, and that's when things absolutely get reported to ATC in real time, along with a best estimate of location of the laser, and a police helo (if available) can get dispatched, and if the perpetrator gets caught, I'll gladly non-rev across the country to testify against him.  That sort of intentional malice against an aircraft full of people deserves years in prison, whether or not the device being used was actually capable of blinding somebody at the range involved.  Since a lot of these devices are from a very large and very unsavory country (which exports lethal drugs in great quantity, tortures their own citizens, lies about a lethal virus they created, etc etc), I wouldn't trust that the devices necessarily meet the stated power limits -- and certainly not when one is being pointed at my cockpit!
As for the question if the limits that the FAA sets should be different, that's really a question of what it takes to damage a person's vision under different conditions.  Obviously the goal is to be cautious & conservative, and even without permanent damage, the distraction effects of the bright lights and any after-effects that persist for seconds or minutes can have repercussions for pilots that are more serious than in other settings.